Photolithography has been used for patterning a substrate (e.g., a wafer) in order to form various features of an integrated circuit (IC). In a typical photolithography process, a photoresist (or resist) layer is formed over a substrate and is exposed to a radiation to form latent images of an IC. Subsequently, it is developed in a developer (a chemical solution) to remove portions of the resist layer, thereby forming a resist pattern. The resist pattern is then used as an etch mask in subsequent etching processes, transferring the pattern to an underlying material layer. The critical dimension of the resist pattern is generally limited by the photolithography process, such as the optical wavelength used for exposing the resist layer. To create patterns that are smaller than the optical resolution of a photolithography process, new materials and new processes are desired.